The present invention relates to an apparatus for applying a liquid sample onto a culture medium with a prescribed quantity and distribution, comprising a syringe, a movable nozzle connected to the syringe through a line, a table for a culture medium container, a container for sample liquid, a container for desinfectant, and a control system and movement mechanism for displacing the nozzle.
In a prior art apparatuses of this type, for example, U.S. Pat. Nos. 3,799,844; 3,892,632 and 3,962,040, the sample liquid is applied in a spiral shape onto a so-called agar culture medium. The agar culture medium is applied to the culture medium container, such as a Petri dish, as uniformly as possible and with a prescribed thickness. However, in practice this thickness varies several millimeters. As a result thereof the accurate angular positioning of the nozzle resting on the culture medium is complicated.
Furthermore, problems may arise in the prior art apparatus because the manual desinfection of the line and the nozzle are not carried out properly, which may cause cross-infections of samples.